Field of the Invention
This invention relates to buckets for hydraulic excavators, front-end loaders and backhoes and more particularly, to a linkage connection which loosely and yet securely mounts a hydraulic excavator or other bucket on a hydraulic excavator or alternative equipment and facilitates enhanced positioning capability of the bucket on the equipment, particularly in the unloading or cleaning of ballast, rock or other particulate matter from gondola rail cars and other confined areas. In a preferred embodiment the linkage connection is characterized by a pair of bucket flanges which extend rearwardly from the typically elongated bucket, in horizontally spaced-apart relationship with respect to each other. A pair of circular linkage openings is provided in vertically spaced-apart relationship with respect to each other in each bucket flange, a circular pin plate is disposed in each linkage opening and a linkage pin extends through the circular pin plate. A rotation linkage and a dipper stick linkage, typically of a hydraulic excavator, are connected to the linkage pins of the respective pin plates of each bucket flange, such that the excavator bucket is supported on the pin plates. The diameters of the pin plates are slightly smaller than the diameters of the respective linkage openings in which the pin plates are disposed, such that the excavator bucket is capable of slight, substantially universal movement on the hydraulic excavator, most importantly tilting in a generally vertical plane, pivoting in a generally horizontal plane and generally vertical and horizontal shifting movements. Accordingly, because of the loose yet secure articulation of the bucket on the excavator, front-end loader or backhoe, during the unloading or cleaning of the particulate material from gondola railcars the bucket is capable of substantially following or conforming to the contour of the rail car floor and walls as the bucket is maneuvered to scoop the material from the car. This facility enables the bucket to reach corners and crevices of the railcar in a more effective manner than can be achieved with conventional, fixed articulation hydraulic buckets. In another embodiment, the linkage connection is characterized by a pair of side bucket flanges which extend rearwardly from the bucket in horizontally spaced-apart relationship and a middle bucket flange which extends rearwardly from the bucket between and slightly above the side bucket flanges. The rotation linkage of the hydraulic excavator is connected to the middle bucket flange and the dipper stick linkages of the machine are connected to the respective side bucket flanges, by means of the respective linkage pins and pin plates which are disposed in linkage openings provided in the respective bucket flanges.
Conventional hydraulic excavators, front-end loaders and backhoes typically include a pair of parallel "dipper sticks" which extend from the cab and are attached by means of pivot pins to respective flanges which are provided on the rear surface of an elongated bucket. Typically, a rotation link is connected to the bucket, either directly above each dipper stick or above and between the dipper sticks, such that piston-actuated movement of the rotation link causes the bucket to pivot on the dipper sticks. While the bucket can be rotated on the dipper sticks in a generally vertical, forwardly-extending plane defined by the dipper sticks and the rotation link or links, this arrangement does not enable slight tilting in a vertical plane, pivoting in a horizontal plane or vertical and horizontal shifting movements of the bucket on the machine.
Hydraulic excavators and other hydraulic equipment are commonly used to clean or unload ballast, rock, dirt or other particulate material from gondola railcars, typically by lowering the excavator into the railcar and operating the excavator bucket to scoop the material from the floor of the car. Because the excavator bucket is conventionally rigidly attached to the excavator, the rigid excavator bucket is incapable of following the contour of the floor and walls of the railcar and the excavator thus must be repeatedly repositioned in the car when the material is being removed from the crevices and corners where the walls meet each other and the floor of the car. This necessity of repeatedly repositioning the excavator is particularly problematic due to the narrow confines of the gondola railcar, which substantially limits the repositioning capability of the excavator. Consequently, the fixed articulation buckets of conventional hydraulic excavators and other equipment, such as front-end loaders and backhoes, are substantially incapable of reaching corners and crevices of the railcar, and the ballast or other particulate matter must typically be manually removed from these inaccessible areas, thus requiring additional time, labor and expense in the unloading or cleaning operation.